Apparatus for producing tubular ingots



B. BROWNSTEIN APPARATUS FOR PRODUCING TUBULAR INGOTS June 6, 1933.

5 Sheets-Sheet 1 Original Filed 001:.v 21, 1930 ro ufnsf in June 6,1933. B. BROWNSTEIN APPARATUS FOR PRODUCING TUBULAR INGOTS OriginalFiled Oct 21, 1930 5 Sheets-Sheet 2 A? lifirourns7ei-re l atented June6, 1933 BENJAMIN BBOWNSTEIN, or nLLwooD CITY, PENNSYLVANIA I.AI'YPARAT'US FOR PRODUCING TUBULAR INGOTS Original application filedOctober 21, 1930, Serial No. 490,229. Divided and this application filedDecember This invention relates to the art of making hollow ingots as apreparatory step to forming seamless tubes, pipe or hollow shafting andthis present invention particularly relates to the apparatus forproducing such ingots, the present application being a division ofapplication, Serial No. 490,229, filed October 21, 1930 on Method of andapparatus for producing tubular ingots.

It was proposed a number of years ago to produce hollow ingots bycasting the molten metal around a metallic core. This process ispractically inoperative because of the fact that molten metal whilecooling and solidifying contracts, the force produced by contractionincreasing as solidification continues. Now when a core of metal isinserted in the mold and when molten metal is.

poured around it, the metal freezes'around the core, while at the sametime heating the core to a high temperature, which softens the core andcauses it to become distorted in shape. This softening and distortedcondition of the core, together with the contractive force of the metalcast around the core, makes it practically impossible to extract thecore from the ingot, particularly so when the molten metal is in a largemass.

Another method proposed which is exemplified by the patent to James442,895 of December 16, 1890, consists in piercing the ingot with apiercing bar while the metal is in a molten state. When piercing moltenmetal, the piercing bar must be kept in the molten metal long enough toallow the metal to set or solidify, and hence when that state arrives,the same conditions are present as previously referred to.

'If the piercing bar is withdrawn too soon, 4 the molten metal will flowout from the bottom and the result of this outflow can be readilyconceived. In this patent, the molten metal is pierced from the bottomand thus the molten metal is caused to leak out from the bottom,freezing around the piercing bar Serial No. 584,234.

and gripping it so that the piercing bar cannot be returned withoutsticking in the gland. This tends also to burn out the packing in thestufling box when the gland gets excessively hot from the molten metal,but the process is particularly impractical in that the piercing barmust be kept in the molten metal until it becomes solidified, causingthe piercing bar to soften, become distorted and preventing theextraction of the piercing bar from the ingot.

The making of an ingot with a hole cast in it as an ordinary casting hasbeen tried many times, but without success, due to the greatdiliiculty'in removing the coreif made of any kind of metal. Sand coresoffer the samedifiiculties in removing them from the ingots. Hence thecost is very high, production is low and these two factors are enough toprevent the'process from being adopted.

Hollow ingots produced directly in the ingot mold after the molten metalis poured into the mold have never been made as far as I am aware, atleast by any practical process.

It has also been proposed to make shells, pipe and like articles byusing a piercing press to produce the shell but such articles areinvariably made from short billets heated at a high temperature,pierced, drawn out in a hot draw bench and the-crop ends cut off. Thepipe resulting from this process are short in length and expensive. Itlong lengths are required, they must be reheated and rolled in a rollingmill and sized to the proper diameter. These operations add greatly tothe production cost and hence are, not used for regular pipe production.

In the last named process, the blanks, from which the shell or shortsection of pipe is to be made by a piercing bar are in the form ofbillets. A billet is the result of many rolling passes after the ingotis castin the mold and hence in operating up a i the operation is to bepreceded by the following operations, namely, (1) the ingot is cast; (2)stripped from the mold; heated in a soaking pit; (4) rolled in ablooming mill into blooms; (5) cut into short lengths; (6) heated androlled into billets and cut into short lengths for makingpipe. Theseoperations, added to the operations for making pipe from the billetitself, make ten operations for making a length of pipe.

My improved method of making ingots is based upon the fact that when aningot is cast, the metal cools from without, that is, the exterior coolsfirst and the interior cools last and by my process, broadly speaking,when the metal in the interior has cooled to a completely solidified butplastic condition, and is beyond, therefore, a molten condition. I thenpierce the ingot, which at this time otters the least resistance to thepiercing bar. Furthermore, inasmuch as the metal is in a plasticcondition, the piercing of the ingot causes all cracks and flaws to fillup under pressure and hence produces a sounder ingot. Now when a billetis heated-or an ingot is reheated, after it is cooled, even though it isstill in a hot state but solidified, the exterior heats first and theinterior heats last.

Hence to heat a billet so that the interior will be in the same plasticstate as the ingot after it is cast, will cause the exterior to meltaway as it is heated first. Therefore, piercing cannot be utilized as itcan with the ingot. To pierce .a short billet from which, for instance,a six inch shell is made takes 1,500.000 pounds of pressure whereas ifthe metal be in aplastic state, it would take one third or less of thispressure to pierce the billet, that is. a small billet from which athree inch pipe is made. My invention contemplates casting the ingot ina mold, piercing the ingot in the mold, while the metal is in a plasticstate and offering the least resistance to the piercing bar, strlppingthe ingot from the mold with no crop end loss, or with a smallcrop endloss and cutting ofi' the crop endif a crop-end ingot is made.

Since ingots used in my process will weigh from 2,000 to 20.000 pounds,each, and the pipe lengths will weight from 50 to 2,500 pounds each, itwill be seen that many lengths of pipe may be made from each ingot by myprocess as against one or two pipes made by piercing abillet.Furthermore, by my invention, less machinery and equipment is required,thus meaning a cheaper production cost per pipe and a small investmentfor plant.

With these facts in view, the general object of the present invention isto provide an apparatus of a relatively simple character whereby aningot may be 'cast, pierced and stripped in accordance with the methodabove outlined with the fewest possible steps.

Other objects will appear in the course of the following description.

My invention is illustrated in the accompanying drawings, wherein Figure1 is a section on the line 11 of Figure 2;

Figure 2 is a vertical section of one form of my apparatus, the piercingbar and the cross head being in elevation;

Figure 3 is a fragmentary vertical section on the same plane as Figure2, but showing the piercing bar at the end of its piercing movementFigure at is a longitudinal sectional view of an ingot after being castand pierced and before being cropped;

Figure 5 is a like view to Figure 4 but showing another form of ingot;

Figure 6 is a fragmentary section of the lower portion of the ingot moldand a modified form of stool therefor;

Figure 7 is a section on the Iin I' -T of Figure 6;

Figure 8 is a section on the same line as Figure (5 but showing theslides withdrawn and the ram in place;

Figure 9 is a section on the line 99 of Figure 7;

Figure 10 is a section on the same plane as Figures 2 and 8 but showinga modified form of stool and slide; .1

Figure 11 is a fragmentary section at right angles to Figure 10;

Figure 12 is a like view to Figure 11 but shmving a modified form ofslide;

Figure 12} is a longitudinal sectional view of an ingot made by themechanism illustrated in Figure 12;

Figure 11 is a top plan view of any one of the ingots to show that theingot may have rounded sides;

Figure 15 is a. fragmentary longitudinal sectional view through an ingotpierced or ruptured by a piercing bar.

Referring to Figure 2, 10 designates an ingot mold such as is used forthe production of the ingot A in Figure This ingot mold 10 is placedupon a metal stool 11, and clamped to the stool by clamps 12 engagingthe mold or by any other suitable means. The stool is annular in form toprovide a central passage 13 and prior to the casting of the ingot abottom plug 14 is disposed in this opening and cemented in place by fireclay 15. The. molten metal M is then poured into the mold and allowed tocool until it is in a plastic state. The mold and the stool are thendisposed in a press and a piercing bar 16 is driven downward through thetop of the mold, that is, through the plastic metal within the ingotmold while the plug is supported by a ram 18 from below. Itwill be seenfrom the drawings that the body of the piercing bar tapers upward fromthe piercing nose 17 and the piercing nose tapers downward from the bodyof the piercing bar, terminating in a rounded point. This constructionof the piercing bar and nose enables the piercing and strippingoperations to be done with a minimum of wear and tear on the piercingbar and nose and hence prolongs the life of the piercing bar and nosewhich means less delay in mill operation and greater and more economicaldaily production. holding the supporting ram is greater than the forceoperating the piercing bar, hence allowing the piercing bar to piercethe ingot to within a predetermined distance from the bottom of theingot as shown in Figures 2 and 5. The force holding the supporting ramis then released and the piercing bar continues to move downward asshown in Figure 3, beyond the upper face of the stool producing thecylinder shown in Figure 4. It is to be noted that the opening in thestool 11 has downwardly diverging walls and is larger than the piercingbar so that the crop end a is formed as shown in Figure 3 when thepiercing bar is forced beyond the upper face of the stool.

The piercing bar is surrounded by the stripper 19 sothat when thepiercing bar is moved upward, the ingot is held in the mold and strippedfrom the piercing bar by the stripper. The stool with the mold and ingotis then removed from the press, clamps released, and the ingot moldremoved from the stool.- The ingot is then stripped from the mold andthe crop end a "of the ingot A or a of ingot A is then cut off by a sawor torch, producing a complete hollow ingot from which any size pipe,tube or hollow shafting within the range of the ingot can be rolled. Theplug is removed from the supporting ram for use in the next mold. InFigure 2 I have illustrated generally speaking the means whereby thepiercing bar, the stripper and the cross head are carried, it beingunderstood, however, that any suitable means may be provided for thispur-' pose. In this figure, H designates the cross head carrying thepiercing bar and H the holder for the piercing bar. B designates thestripper cross head which carries the stripper 19, this beingconnectedto the piston rods B. The stool 11 is supported upon the crosshead C through which the support ing ram 18 operates. The piercing bar,the stripper, cross head and the supporting ram may be operated byhydraulic means, by compressed air or by any other suitable medium.

In Figures 6 to 9 I have illustrated another ingot mold for producingsuch an ingot as that shown at A in Figure 4. The same ref erencenumerals have been used for the stool,

the ingot mold, the piercing bar and the stripper. In thiscase, however,the bottom plug 14 is supported by two oppositely disposed The forceslides 20 located in slideways 20 formed in the stool. The top of thebottom plug is greased or oiled with heavy oil and fire clay 21 isapplied to close the hole in the stool and cover the plug, the oil orgrease acting to prevent the plug from sticking to the clay when it ishardened. The molten metal is then poured into the mold and when cooledto a completely solidified but plastic state, the supporting slides 20are withdrawn by means of the slide operating levers 22 and 23 shown inFigure 7. These slide operating levers are pivoted at 2 k within thestool by fulcrum pins and the inner ends of the levers are rounded andfit within openings 25 formed in the slides 20. The lever 22 is pivotedupon a fulcrum pin 24 and between the inner end of the lever 22 and thisfulcrum pin 24:, is pivoted one end of a link 26 extending through thepassage 27 formed in the stool and piv oted to the lever 23 at a pointoutward of its fulcrum pin so that the levers will operate in oppositedirections. "x

A wrench bar or handle 28 is applied to the extremity of the lever 22 tomove this lever. Thus by shifting the wrench handle in one direction,both slides will be shifted inward, that is, into a position to supportthe plug 14 or shifted outward to release the plug. When the slides areclosed and the plug is placed on the slides, a lock pin 29 is insertedthrough the stool and through an aperture formed in the lug 30projecting through the lever 23 to thus lock the operating slide leversand prevent the supporting slides from moving, thus keeping the plug inits proper location on the stool. \Vhen the metal is cooled to acompletely solidified but plastic state, the supporting slides are movedby the handle 28 and the plug drops out from the bottom of the stool.The ingot mold is then placed in a press having a piercing bar and asupporting ram as shown 'in Figures 8 and 9, and is then operated on inthe same manner as the ingot mold previously described. In this casealso the wall of the opening 13 is downwardly flared and has a diametergreater than that of the piercing bar whereby the piercing bar may passinto said opening in the stool as shown in Figure 9 and produce aprojecting hollow crop end a. In Figures 10 and 11 I have shown an ingotmold for forming an ingot A and A. The mold 10 is formed of a steelcasting and provided with a cast iron inner mold shell 10'.

Stool 11 has an opening 13 and has a slidebeen withdrawn, to permit apunch bar to punch out the bottom of the ingot. The aperture 34 is lessin diameter than the diameter of the piercing bar above its taperedlower end and the wall defining the upper end of this aperture 34constitutes a cutting die plate coacting with the punch 35 to enable thepunch to cut out the bottom of the pierced ingot.

The metal is poured and when in a state where the metal has completelysolidified but is still plastic, the piercing bar 16 is moved downwardto a predetermined distance from the top of the slide. The movement ofthe piercing bar is then reversed and the piercing bar withdrawn whilethe ingot is held in the mold and stripped from the piercing bar by thestripper 19. The mold is then moved beneath a punch bar 35 and the slide32 is shifted to bring the center line of hole 34 in alinement with thecenter line of the mold. The punch bar is then forced down and thebottom of the pierced ingot is punched out as shown in Figure 5, wastedropping out through the hole in the bottom of the stool, as shown inFigure 11.

The punch bar has a head at its lower end smaller than the diameter ofthe piercing bar and this head has, of course, a sharp cutting edge atits lower end with which the sharp cutting edges of the slide openingsecure a proper action for the punch in punching out the lower end ofthe ingot as shown in Figures 11 and 12. The slide shown in Figure 12 isprovided with a relatively deep cylindrical opening to permit thepiercing bar to produce a cylindrical extension and at the lower end ofthis opening 34, there is a smaller opening 34 provided with a cuttingedge for the purpose of punching out the bottom of the cylindricalextension. 'llheretore, it will be seen that the slides 32 anud 32 shownin Figures 11 and 12 not only. act as the bottom for the mold butprincipally for the purpose of provid ing a cutting die plate to enablethe punching bar to cut out the bottom of the pierced ingot.

In Figure 12 there is shown the same general structure as in Figure 11but With slide 32 having a deeper section with a recess 34% above theopening 34. which is greater in diameter than the piercing bar, thusforming the ingot shown in Figure 13 with the elongated end (1*.

In the use of this mmlitication, the piercing bar is moved downward to apredetermined distance from the top of the slide. The slide is thenmoved until the center line of the hole is in line with the center-lineof the mold and then the. piercing bar is moved a further distancedownward to a predetermined amount, prodiu'ing the cylinder end ofthe-ingot shown in Figure 4. The piercing bar is then withdrawn from theingot, the stripper 19 preventing the ingot from being lifted from themold. The ingot mold is brought beneath and in line with the punch bar35 which is moved down and the bottom of the cylinder end is punched out(see Figures 12 and 13) waste dropping out through the hole in thebottom of the stool. The slide can be operated by any suitable means, asfor instance, by hand or motor, through a rack and pinion or screw. Thishas not been shown inasmuch as many different means may be used for thispurpose, all of which are obvious.

It is to be particularly noted here that in my apparatus the punch baris never used for piercing the ingot but only for punching out the endof the ingot and that in my apparatus, a piercing bar is used forpiercing the ingot, this piercing bar being moved nearly to the lowerend of the ingot or moved to produce the extension shown in Figure 4 andthen the punch is used to punch out this lower end of the ingot as shownin Fig are 12. In other words, I pierce the ingot first and after thepiercing bar is withdrawn from the ingot, I follow with a cool punch barwhich has a sharp cutting edge at its lower end whose diameter issmaller than the diameter of the piercing bar. This is for the reasonthat a punch bar having an enlarged cutting head when it is forced downthrough a billet or through even an ingot which is solidified, yetplastic, will become distorted or bend or buckle at its middle when acompressing force is applied to it and hence the distorted punch barwill have its cutting head disposed eccentrically to the central openingthrough which the punch bar must pass and which it must more or lessclosely fit. It will be seen that since the punch bar will deviate fromthe true center of the ingot, the punch bar will not enter the hole inthe slide 32, for instance, and hence will not punch or shear the bottomof the ingot.

It will be seen that with my construction, however, the punch bar 35travels downward through the relatively large opening formed by thepiercing bar and that the punch, therefore, only has to act against thelower end of the ingot and for a relatively short distance so that thereis no strain tending to distort the punch bar or render it eccentric. Topierce or punch and shear in the same operation requires that the punchbar must be provided with a sharp edge at its lower end and if such anedge is provided, it will be burned off by the hot metal where the punchbar is forced downward through the entire length of an ingot to piercethe ingot and the punch will become pitted and blistered. A punch barwith such an edge cannot shear or punch out any metal even though it ishot. p

In Figures 10'to 12 I have illustrated the ingot mold as made in twoparts, that is, of an outer shell 10 and an innershell 10*.

mold. The inner shell is made with a flange 10" at top and bottomoverlapping the outer shell so as to form a positive connection betweenthe shells and prevent the shells from being stripped apart whenstripping the ingot from the mold.

The stripper 19 which strips the in got from the piercing bar isattached to the press and operated by it. The ingot A shown in Figure 5can be made in any one of the molds described. The ingot A shown inFigure 4 can be made in the ingot molds shown in Figures 2, 3, 8, 9 and12. Ingot A Figure 15, can be made in the molds Figures 3 and 9 byallowing the piercing bar to continue in its stroke until the cylinderend is ruptured, and opened to the full size of the piercing bar, makinga hollow ingot with a hole from end to end. The ingots in Figures 4, 5and 15 may all be cropped along the lines XX in dicated in the severalfigures. The irregular metal at end of cylinder produced by rupture maybe cropped after the ingot is stripped from the mold or left until ingotis rolled into tubes or pipe and then cropped.

It is to be understood that in Figure 5 aningot is shown in which thepiercing bar is stopped in its movement before reaching the extremity ofthe ingot and that under these circumstances, the ingot will be cut offon the line X-X, the crop end a being thrown away or remelted. In Figure15, the ingotis shown as having its crop end formed by forcing thepiercing bar entirely through the ingot mold, the crop end being cut offon the line X-X.

The ingot shown in Figure 13 is made byforcing the piercing bar throughthe ingot mold forming the ingot shown in Figure 4 andthen followed byforcing the punching bar 35 into the ingot and punching the bottom outfrom the cylinder. The ingot shown in Figure 11 is made by forcing thepunching bar throu h the closed end and punching the end out. n allforms of my apparatus and in all the steps of the processes described byme, an ingot is formed which after its end is cropped is tubular andwhich may be thereafter rolled to form tubes, pipes, hollow shafts orother like tubular objects.

The reason for producing a cylinder end at the bottom of the ingotinstead of forcing the piercing bar to the end of the ingot is asfollows v The metal as it is poured into the ingot mold solidifies as itcomes incontact with the ingot mold, hence though it is plastic, thismetal is harder than the mass of metal in the center of the ingot.Therefore, it cannot be pierced so easily, as the inward and upward flowof the metal is very slow due to the hardness of the metal and also dueto the great resistance of the large mass of metal at the botto n of theingot and more firmly held to the b ttom and sides of the mold than the'metal within the mass of the ingot.- Second,

in Figures 5 and 10 a large part of the ingot is left as a crop endwhich is expensive waste. Third, it is far easier to draw out the bottomof the pierced ingot into a small cylinder than to cause the metal toflow inward and upward in a confined space as the case happens to be inthe bottom of the ingot mold. Fourth, the crop end produced by thecylinder end shown in Figures 13, 15 and 4 is the least expensive cropend waste.

It is to be understood that the ingot and the corresponding mold mayhave any desired cross section, that is, approximately round,elliptical, triangular or rectangular. In Fi me 14, the ingot is shownas many-sided wit the sides curved instead of straight. This is becausecurved sides are less apt to sag or collapse. Hence the mandrel bar withthe plug will enter the hole of the ingot more easily and there willbeless trouble from that source during the rolling in the first pass. Ofcourse, the shaple of the ingots and the opening extending t rough thesame, will depend entirely upon the shape of the mold and the shape ofthe piercing bar.

It will be seen that with my apparatus, an ingot of the characterdescribed may be formed by piercing the ingot nearly to its lower end,removing the ingot from the mold and cutting off the crop end of theingot or the ingot may be formed by forcing the piercing bar through theingot to a point beyond the stool to thus form a hollow outwardlyprojecting crop end which may be cut off or the piercing bar may beforced entirely through an ingot and into a stool having an aperturelarger than the diameter of the piercing bar, forcing the piercing barentirely through the ingot to form the ingot shown in Figure 15 or thepiercing bar may be forced into the ingot to form the ingot shown inFigures 13 or 14.

1. An apparatus for forming tubular ingots comprising a mold open atboth ends, a stool upon which the mold is supported, the stool having a,central opening, a member disposed in position to close said centralopening but removable therefrom, a piercing bar adapted to be forcedthrough the center the piercing bar is removed, the lower end of thepiercing bar having a rounded con cal tip and being downwardly taperedabove the ti 2. Apparatus for producing hollow ingots comprising a moldopen at both ends, a stool upon which the mold is mounted having acentral opening smaller than the diameter of the mold, the stool beingformed with slideways, means'carried in said slldeways and movablethrough said slideways into POSI- tion across the opening in the stoolor into position to unclose said opening in the stool, a piercing barmovable through the center of the ingot toward the stool, and a stripperholding the ingot in place against the stool when the piercing bar iswithdrawn, the lower end of the piercing bar having a rounded conicaltip and a slightly tapered body above the tip.

3. Apparatus for forming hollow mgots comprising a mold open at bothends, a fixedly supported stool upon which one end of the mold issupported and having a central opening, the stool being formed with aslideway, a slide movable in said slideway, the slide having animp'erforate portion adapted to entirely close the bottom of the moldand having an opening adapted to be brought into alinement with thecentral bottom portion of the mold, a piercing bar movablelongitudinally through the center of the ingot and having a diametergreater than the diameter of said opening in the slide, a stripperholding the ingot in place while the piercing bar 15 removed and a punchmovable longitudinally through the opening 1n the lngot formed by thepiercing bar and having a head with a diameter approximately equal tothe diameter of the opening in the slide and into which the punch ismovable. 4. Apparatus for producing hollow ingots including a mold openat opposite ends, a fixedly supported stool upon which the mold isdisposed and having an opening less in diameter than the diameter of themold, the stool being formed with slide-members movable into positionacross the opening 1n the stool, a bottom plug supported by the slidemember, and means for simultaneously moving said slide members inwardlyto support or outwardly to release the bottom plug, a piercing barmovable longitudinally through the ingot toward the stool and movablethrough said opening in the stool, and a stripper holding the ingot inplace while the piercing bar is removed.

5. Apparatus for forming tubular ingots comprising a mold open at itsopposite ends and formed of an outer shell of cast steel and an innershell of-cast iron, the shells being interlocked with each other againstrelative longitudinal motion, a stool upon which the mold is supported,the stool having a central opening smaller in diameter than the diameterof the mold, a piercing bar movable through the hollow interior of theingot toward the stool, and means for supporting the central portion ofthe ingot while the piercing bar is being forced into the interior ofthe ingot, said means being movable to permit the piercing bar to passthrough the ingot and into the opening of the stool.

6. Apparatus for producing ingots including an ingot mold and a piercingbar, the ingot inold and the piercing bar both being formed with manysided walls each side being outwardly curved.

7. An apparatus for making hollow ingots comprising an ingot mold openat opposite ends,

a stool supporting the mold against downward movement and having acentral opening, a bottom plug insertable therein, a refractory elementto close the space between the plug and stool, clamping means forlocking'the ingot mold to the stool a piercing bar movablelongitudinally through the center of the ingot and through said openingin the stool, and withdrawable means for supporting said plug in thecentral opening in the stool.

8. Apparatus for forming hollow ingots comprising a mold open at bothends, a stool upon which one end of the mold is supported and having acentral opening, the stool being formed with a slideway, a slide movablein said slideway, the'slide having an imperfo-.

rate portion adapted to entirely close the bottom of the mold and havingan opening adapted to be brought into alinement with the central portionof the mold, a piercing bar movable longitudinally through the center ofthe ingot toward said opening in the slide, a punch bar movable throughthe central opening in the slide to punch out the end of the cylinderformed by the piercing bar and having a punching head and a stripperholding the ingot in place when the piercing bar is removed the openingin the slide being of approximately the same diameter as the punch headto permit the passage of the punching head.

9. Apparatus for producing hollow ingots including a mold open atopposite ends, a stool upon which the mold is disposed and having anopening less in diameter than the exterior diameter of the mold, thestool being formed with slideways, oppositely disposed slides mounted insaid slideways and movable into position across the opening in thestool, a bottom plug and supported on said slides when the latter aremoved across the opening in the stool, means for locking the ingot moldto the stool, means for moving said slides simultaneously inwardly tosupport or outwardly to release the bottom plug, means for locking theslides in their inward or outward position, and a piercing bar movablelongitudinally through the iugot toward the stool.

10. Apparatus for producing hollow ingots including an ingot mold openat both ends, an ingot piercing bar rectilinearly movable through themold axially thereof in opposite directions, means for initiallysupporting the central portion of the ingot while the piercing bar ismoving into the mold, said means being shiftable to permit the piercingbar to move inward beyond the inner end of the mold, and a punch movableaxially through the mold and beyond the inner end of the mold to punchout the bottom of the pierced ingot, and means holding the ingot fromretraction from the mold as the piercing bar or punch are withdrawn.

11. An apparatus for forming tubular ingots comprising a mold open atits opposite ends, an ingot piercing barrectilinearly movable into andout of the mold axially thereof in opposite directions, a stool uponwhich the mold is supported, the stool having an opening smaller indiameter than the interior diameter of the ingot mold, a memberassociated with the stool and movable to close the central openingtherein or to provide an opening immediately in advance of the piercingbar and larger in'diameterthan the diameter of the piercing bar at 1tsinner end whereby to form an elongated crop end on the ingot when thepiercing bar moves end the inner end of the mold, and a punch movableinto the ingot after the piercmg bar has been withdrawn to punch out thecrop end formed upon the ingot.

12. An apparatus for making hollow 1n gots including an ingot mold openat its opposite ends, a stool upon which one end of the ingot mold issupported, the central port10n of the stool below the end of the ingotmold being open, an element temporarily disposed in position to closethe opening in the stool while the metal is bein poured into the moldbut removable there rom, a piercmg bar adapted to be forced the ingottoward the stool, and means for holding the ingot in place upon thestool while the piercing bar is being withdrawn, the piercing bartapering downwardly slightly from its upper end toward the nose and thelower end of the piercing bar tapering downward at a greater angle thanthetaper of the body of the bar and terminating in a rounded nose.

13. An apparatus for making hollow ingots including an ingot mold openat its opposite ends, the ingot mold is supported, the central; por tionof the stool below the end of the ingot mold being'open, the openingbeing defined by a downwardly flaring wall, an elementtemporarilydisposable into position to close the opening in the stool to therebypermit the mold to be filled with molten metal, said element beingremovable from such position,

and a piercing bar adapted to be forced be- N through the center of astool upon which one end of through the center of the ingot toward andinto thetopening in the stool.

14. An apparatus for making hollow ingots including an ingot mold openat its opposite ends, a stool upon which one end of the mold issupported, the central portion of the stool below the end of the moldbeing open, a removable element temporarily (lisposable into position toclose the opening into the stool and thereby permit the retention of themolten metal in the mold while hardening and being pierced, said elementbeing removable from this position, a retractible ram movable into theopening in the stool to support said element and the central portion ofthe ingot, and a piercing bar adapted to be forced through the center ofthe ingot toward the stool and ram.

. 15. Apparatus for making hollow ingots including an ingot mold open atits opposite ends, a stool upon which one end of the ingot mold issupported, a slide operating in the stool below the ingot mold, aportion of the slide being imperforate to close the ingot mold andpermit the material of the ingot .to be poured, another portion of theslide having a recessed portion extending downward from the upper faceof the slide, the lower wall of the recess being formed with anopenpunch bar movable downward through the open ng formed through theingot by the piercing bar and having a head movable into the recess inthe slide and through the openstool having a central opening, a memberdisposed in position to close said central open1ng,'a piercing baradapted to be forced through the center of the ingot toward the stool,and a stripper holding the ingot in place when the piercing bar isremoved, the

piercing bar having a piercing nose and the dy of said bar slightlytapering downward to the piercing nose and the piercing nose taperingdownward from the body of the piercing bar at a greater angle than thetaper of the body of the bar and terminating in a rounded point.

17. Apparatus for producing hollow ingots comprising amold open at bothends, a stool upon which the mold is supported having a central openingsmaller than the diameter of the mold, the'stool being formed withslideways, means carried in said slideways ing at the bottom of saidrecess, the slide re- P and movable through said slideways into apositionacross the opening in the stool or into a positlon to unclosesaid opemng 1n the stool, a piercing bar movable through the center ofthe ingot toward the stool and a stripper holding the ingot in placeagainst the stool when the piercing bar is withdrawn, the piercing barhaving a nose and tapering downward toward the nose, the piercing nosetapering downward from the body of the piercing bar at a steeper angleand terminating in a rounded point.

In testimony whereof I hereunto afiix my signature.

BENJAMIN BROWN STEIN

